MOLECULAR STUDIES OF PRIMARY CILIUM BIOGENESIS

原代纤毛生物发生的分子研究

• 批准号: 8641388
• 负责人: Maxence V Nachury
• 金额: $ 30.89万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2015-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8641388
• 关键词: Bardet-Biedl Syndrome; Binding; Binding Proteins; Biochemical; Biological Assay; Cell Polarity; Cell model; Cell surface; Cells; Cilia; Clathrin; Clathrin Adaptors; Clinical; Coat Protein Complex I; Complex; Cystic kidney; Cytoplasmic Tail; Data; Defect; Disease; Docking; Erinaceidae; Etiology; Functional disorder; Goals; Growth; Guanine Nucleotide Exchange Factors; Guanosine Triphosphate Phosphohydrolases; Hereditary Disease; Hydrolysis; Inborn Genetic Diseases; Individual; Integral Membrane Protein; Lead; Liver diseases; Mediating; Membrane; Membrane Proteins; Modality; Modeling; Molecular; Names; Nucleotides; Obesity; Organ; Output; Polycystic Kidney Diseases; Property; Protein translocation; Proteins; Reaction; Receptor Signaling; Recruitment Activity; Research; Research Proposals; Retinal Degeneration; Role; Signal Pathway; Signal Transduction; Sorting - Cell Movement; Surface; Symptoms; Testing; Time; Variant; Vesicle; Weight; base; cilium biogenesis; insight; polymerization; public health relevance; reconstitution; research study; skeletal abnormality; therapeutic development; trafficking

DESCRIPTION (provided by applicant): The primary cilium, a "signaling antenna" projecting at the surface of the cell, is required for the transduction of Hedgehog and planar cell polarity signals and concentrates many signaling receptors on its surface. Furthermore, ciliary dysfunction leads to obesity, retinal degeneration and kidney cysts in the inherited disorder Bardet-Biedl Syndrome (BBS). Yet, the mechanisms of signaling receptor trafficking to the ciliary membrane are not understood. We recently discovered a stable complex of seven BBS proteins, that we named the BBSome and have implicated in vesicular trafficking to the cilium based on its functional interaction with Rab8, a GTPase with a well-established trafficking function whose manipulations directly impact cilium growth. Here, we advance the hypothesis that the BBSome sorts specific transmembrane proteins to the primary cilium. In this research proposal, we will dissect BBSome function within the context of vesicular transport to the cilium through the following aims: 1- Identify the transmembrane proteins transported by the BBSome towards the cilium. Known ciliary transmembrane proteins will be tested for a BBSome requirement in their trafficking to cilia and we will establish a time-resolved trafficking assay to identify the donor compartment from which the BBSome selects its cargoes. 2- Dissect the mechanisms of BBSome targeting to cilia. We will assay the function of BBSome-binding proteins in mediating the recruitment of the BBSome to cilia. 3- Characterize the functional interplay between the BBSome and Rab8. In preliminary studies, we have found that the BBSome interacts with Rabin8, the GDP/GTP exchange factor for Rab. Here, we will seek to understand how the BBSome modulates the activity and localization of Rabin8 to enable Rab8 entry into the cilium. In conclusion, our model for BBSome function has significant implications for the etiology of Bardet-Biedl syndrome: in a model where the BBSome targets specific signaling receptors to the cilium, each individual symptom of BBS results from the disruption of a specific ciliary signaling pathway.

描述（由申请人提供）：刺猬和平面细胞极性信号的转导所必需的原发性纤毛，即在细胞表面上投射的“信号传导天线”，并在其表面上集中了许多信号受体。此外，睫状功能障碍会导致遗传疾病Bardet-Biedl综合征（BBS）中的肥胖，视网膜变性和肾脏囊肿。然而，尚不清楚信号传导受体运输到睫状膜的机制。我们最近发现了一种稳定的七个BBS蛋白的复合物，我们将其命名为BBSOME，并根据其与RAB8的功能相互作用（一种具有完善的运输函数的GTPase，其操纵功能直接影响纤毛生长的GTPase，它都与囊泡运输有关。在这里，我们推进了一个假设，即BBSOME将特定的跨膜蛋白分类为原代纤毛。在这项研究建议中，我们将通过以下目的在囊泡转运到纤毛的背景下剖析BBSOME功能：1-确定由BBSOME运输的跨膜蛋白向纤毛运输的跨膜蛋白。已知的睫状跨膜蛋白将在贩运纤毛的贩运中测试BBSOME的要求，我们将建立一个时间分辨的贩运测定法，以确定BBSOME从中选择其货物的捐赠者舱。 2-将BBSOME靶向纤毛的机理解剖。我们将测定BBSOME结合蛋白在介导BBSOME募集到纤毛中的功能。 3-表征BBSOME和RAB8之间的功能相互作用。在初步研究中，我们发现BBSOME与Rabin8（Rab的GDP/GTP交换因子）相互作用。在这里，我们将寻求了解BBSOME如何调节Rabin8的活动和定位，以使Rab8进入纤毛。总之，我们的BBSOME功能模型对Bardet-Biedl综合征的病因具有重要意义：在BBSOME将特定信号受体靶向纤毛的模型中，BBS的每个个体症状是由特定纤毛信号通路的中断引起的。